---
title: "alex-flexdashboard"
author: "Hoang Phong Nguyen"
date: "5/21/2021"
output:
flexdashboard::flex_dashboard:
orientation: rows
vertical_layout: fill
source_code: embed
---
```{r libraries, echo=FALSE}
library(flexdashboard)
library(tidyverse)
library(naniar)
library(ggplot2)
library(kableExtra)
library(plotly)
```
```{r}
# read tidy data
fatalcrashes <- read.csv(here::here("data/cleaned_fatalcrashes.csv"))
fatalities <- read.csv(here::here("data/cleaned_fatalities.csv"))
```
Speed Limit Analysis {data-icon="fa-tachometer-alt"}
====================
```{r hp-clean-fatal}
fatalities$Speed.Limit <-
str_replace(fatalities$Speed.Limit, "<40", "39")
fatal_sl <- fatalities %>%
mutate(Speed.Limit = as.numeric(Speed.Limit)) %>%
select(Crash.ID, Year, State, Speed.Limit) %>%
group_by(Year, Speed.Limit) %>%
count() %>%
pivot_wider(names_from = Speed.Limit,
values_from = n) %>%
mutate("<= 40" = sum(`10`, `39`, `40`, `20`, `30`, `5`, `15`, `25`,
na.rm = T)) %>%
mutate("70-90" = sum(`70`, `75`, `80`, `90`, na.rm = T)) %>%
mutate(">= 100" = sum(`100`, `110`, `130`, na.rm = T)) %>%
select(Year, `<= 40`, `50`, `60`, `70-90`, `>= 100`) # "NA")
```
```{r hp-clean-crash}
fatalcrashes$Speed.Limit <-
str_replace(fatalcrashes$Speed.Limit, "<40", "39")
crash_sl <- fatalcrashes %>%
mutate(Speed.Limit = as.numeric(Speed.Limit)) %>%
select(Crash.ID, Year, State, Speed.Limit) %>%
group_by(Year, Speed.Limit) %>%
count() %>%
pivot_wider(names_from = Speed.Limit,
values_from = n) %>%
mutate("<= 40" = sum(`10`, `39`, `40`, `20`, `30`, `5`, `15`, `25`,
na.rm = T)) %>%
mutate("70-90" = sum(`70`, `75`, `80`, `90`, na.rm = T)) %>%
mutate(">= 100" = sum(`100`, `110`, `130`, na.rm = T)) %>%
select(Year, `<= 40`, `50`, `60`, `70-90`, `>= 100`) #, "NA")
```
Row
------------------
### Table 6.1: Yearly number of fatal crashes by speed limit
```{r hp-table}
crash_sl %>% kbl() %>%
kable_minimal()
```
```{r hp-pivot-longer}
crash_sl_l <- crash_sl %>%
pivot_longer(crash_sl, cols = -Year,
names_to = "Speed_limit", values_to = "n_crashes")
fatal_sl_l <- fatal_sl %>%
pivot_longer(fatal_sl, cols = -Year,
names_to = "Speed_limit", values_to = "n_fatalities")
```
### Figure 6.1: Comparing proportion of yearly fatal crash by speed limit
```{r hp-fig-year}
crash_sl_l %>% mutate(Speed_limit = fct_reorder(Speed_limit, n_crashes)) %>%
ggplot(aes(x = as.factor(Year),
y = n_crashes, fill = Speed_limit)) +
geom_col(position = "fill") +
scale_fill_brewer(palette="Set1") +
theme(axis.title.x = element_blank())
ggplotly()
```
```{r hp-clean-compare}
comparison_crash_fatal <-
left_join(crash_sl_l, fatal_sl_l,
by = c("Year", "Speed_limit"))
comparison_pct <- comparison_crash_fatal %>%
group_by(Speed_limit) %>%
summarise(n_crashes = sum(n_crashes),
n_fatalities = sum(n_fatalities)) %>%
mutate("perc_fatalities" = (n_fatalities - n_crashes)*100/n_crashes) %>%
arrange(perc_fatalities)
comparison_l <- comparison_pct %>%
select(-perc_fatalities) %>%
pivot_longer(cols = c(n_crashes, n_fatalities),
names_to = "type", values_to = "n_fatal")
```
Row
--------------
### Figure 6.2: Comparing number of fatalities and fatal crashes by speed zone
```{r hp-fig-compare}
comparison_l %>%
mutate(Speed_limit = fct_reorder(Speed_limit, n_fatal)) %>%
ggplot(aes(x = Speed_limit,
y = n_fatal, fill = type)) +
geom_col(position = "dodge") +
theme_bw() +
scale_fill_brewer(palette="Set1") +
labs(x = "Speed Limit (km/h)",
y = "Count")
ggplotly()
```
### Figure 6.3: Percentage difference between fatalities and fatal crashes
```{r hp-fig-percent-diff}
comparison_pct %>%
mutate(Speed_limit = fct_reorder(Speed_limit, perc_fatalities)) %>%
ggplot(aes(x = Speed_limit, y = perc_fatalities)) +
geom_col(fill = "light blue") +
theme_bw() +
labs(x = "Speed Limit (km/h)",
y = "Percent")
ggplotly()
```
### Analysis
- Table 6.1 showed between 2010 and 2020, fatal crashes is reduced for higher speed zones but increased for lower speed zones
- The speed zone >= 100 km/h accounts for nearly 50% of all fatal crashes in Australia
- Number of fatal crashes and fatalities both increased with speed limits
- Fatalities is 3% higher than number of fatal crashes at lower speed zone, but increase up to 13% for higher speed zone
